Field of the Invention
This invention relates to techniques for flying magnetic heads used with magnetic disk drives and, more particularly, to a method of manufacturing flying magnetic heads of a composite type using a thin-film-laminated core as a head core (or a head chip).
Recently, composite type flying magnetic heads, which use as a head core a thin-film-laminated core obtained by laminating on a substrate a magnetic thin film comprising an Fe-Si-Al alloy (Sendust), an amorphous magnetic material, an iron nitride type alloy, etc., have attracting attention because they can be used for magnetic disk drives and the like, permit high density recording and permit track width reduction.
FIG. 13 shows a flying magnetic head commonly called a composite type, which has been proposed earlier by the present applicant as Japanese Patent Application No. 84441/1991. This flying magnetic head comprises a head 1 and a slider 2 and, although not shown, is connected to an actuator of an associated apparatus via a leaf spring support mechanism.
This flying magnetic head uses a bonding glass m having a high melting point in lieu of a low-melting molding glass which has hitherto been used for bonding the head core 1 to the slider 2. Thus, it can greatly reduce the exposed area of the glass layer m on an air-bearing-surface (hereinafter referred to simply as "ABS") 4 and extremely improve the CSS (contact start characteristic, thus extremely improving the reliability as a whole.
However, even the composite type flying magnetic heads using such a thin-film-laminated core are required to provide improved performance. Particularly, it is desired to increase the number of turns of a winding 200 provided in the head core 1 from 40 turns at present to turns, for instance.
To this end, it is necessary to expand a wiring groove 20 formed in a C core 18.
To meet this aim, the inventors produced a head core 1 with expanded wiring groove 20 by forming a transversal window groove 19A in an I bar 19, as shown by phantom lines. In this case, however, the corresponding end portion of the head core 1, bonded to the slider 2, popped during the processing of the ABSs such as a processing to form edge grooves 100 and a top center groove 101 and also a processing to form inclined surfaces 102 and 103. It was thus impossible to obtain smooth ABSs. This seems to be due to a reduction of the mechanical strength of the head 1 itself and hencereduction of the resistance of the ABS surfaces againstgrinding, caused by the formation of the transversal window groove 19A in the I bar 19.
In order to provide a composite type flying magnetic head, which permits increase of the turns number of the head core winding to enhance performance without reducing the mechanical strength of the head core, facilitates the processing of the ABS, permits a smooth ABS to be obtained and uses a thin-film-laminated core as the head core, the inventors produced a flying magnetic head of composite type, as shown in FIG. 1, which comprises a slider having an ABS, an I core bar having a magnetic thin film layer, one end face of the I core bar being bonded to the entire area of one end face of the slider such that the magnetic thin film layer of the I core is mated with the ABS, and a C core having a magnetic thin film layer, the C core being bonded to the other end face of the I core bar such that the magnetic thin film lamyer of the C core bar is mated with the magnetic thin film layer of the I core bar, the I core bar being formed at a position thereof corresponding to a wiring groove with an inclined window groove having a predetermined inclination angle .theta..